SEALED TERMINAL FOR A COATED OPEN WIRE

Abstract: The invention relates to a sealed terminal for a coated open wire, comprising a body member (1) and a conical fastening sleeve (2) connected therewith as well as a clamp element (3) for fastening the terminal to an insulator. The body (1) is provided with a wire-end receiving space (9) included in the axial extension of said sleeve-like fastening socket (2). The body (1) is provided with screws for providing an electrical contact between the wire end inserted in said space (9) and the body (1). A coupling element (4) can be used for clamping a branch wire into contact with the body member (1). The tensile load of a wire is taken up by means of wedge elements (7) included in the conical sleeve (2).

Description: Sealed terminal for a coated open wire The present invention relates to a sealed terminal for a coated open wire, comprising a body member, a clamp element included in the body member for fastening the terminal to an insulator, a coupling for connecting a branch wire, and a sleeve-like fastening socket provided with fastening ele¬ ments for taking up the mechanical stresses of a wire. When using such terminals, the end of a wire is stripped of the wire insulation over a certain distance and the sealing is effected by means of separate protectors, ■ such as e.g. shrinking plastics, used for surrounding the junction point between a terminal and a wire. The branch wire is connected by means of a separate coupling or cable grips which must be clamped around the wire with a tool. With the prior known terminals, the electrical contact is poor because of a plurality of coupling transition points. The prior known terminals include at least 3-4 transfer resistances produced by transitions. In addition, the prior known terminals are relatively long, making the installation thereof inconvenient. An object of the invention is to provide an improved sealed terminal capable of utilizing a per se known automatically locking fastening sleeve for taking up the stresses of a wire while reducing the number of transfer resistances to at least two and reducing the terminal length for an improved installability. This object is achieved on the basis of the characterizing features set forth in the appended claim 1. The non-independent claims disclose preferred ways of prac¬ ticing the invention relating to the most preferred exempla¬ ry embodiment of the invention. The invention will now be described in more detail with reference made to the accompanying drawings, in which fig. 1 shows a sealed terminal of the invention in a side view and partially cut away; fig. 2 is a plan view of the same terminal. The terminal includes a body member 1 which is made of profiled aluminium and provided with a fastening element 3 for attaching the terminal to an insulator. The body 1 is provided with a longitudinal extension which is a sleeve-like fastening socket 2, comprising a conical sleeve provided thereinside are wedge elements 7 clamping against the surface of a wire. A spring 8 is used for bias¬ ing the wedge elements 7 towards the tapering direction of the cone 2 whereby, upon the insertion of a wire, the wedge elements 7 are able to yield as the spring 8 is compressing. As the wire is being pulled outwards, the wedge elements 7 clamp with a major force against the wire surface providing a locking which takes up the mechanical tensile stress. Such sleeve-like fastening sockets are prior known. In the inven¬ tion, however, it is used for providing a novel type of assembly with the body member 1. Therefore, the body 1 is provided with a wire-end receiving space 9 included in the axial extension of said sleeve-like fastening socket 2. The body member 1 includes threaded holes, provided with moment screws 10 whose ends extend inside the space 9 and provide an electrical contact as the screws 10 are tightened against the wire end within the space 9. In view of connecting a branch wire, the body 1 is fitted a coupling element 4 (in the present case, two elements side by side) by using screws 14. The coupling elements 4 and the body 1 are provided with a first pair of jaws, said jaws including meshed surfaces provided with teeth 5 capable of piercing the wire insulation. A second pair of jaws includes meshed or contact surfaces 6, between which can be fitted a flash barrier horn or a working earth conductor. The teeth 5 may have a length sufficient for piercing the branch wire coating and, thus, the branch wire coating need not be stripped off. The fastening cone 2 is connected to the body as follows. The base portion of said fastening cone or sleeve 2 is surrounded by a locking ring 11 which is fastened with screws 13 to brackets 15 included in the bottom of the body 1. The base of said fastening cone or sleeve 2 is provided with an annular bulge or boss 12, fitted between the bottom of the body 1 and the locking ring 11. Thus, this annular boss 12 engages behind the locking ring 11 and transmits the tensile stress of a wire from the sleeve or cone 2 to the locking ring 11 from which the stress or loading transmits by way of the screws 13 to the body member 1. However, the electrical contact need not be carried over the transition point between the sleeve or cone 2 and the body member 1 but the electrical contact is produced directly on the aluminium body 1 as the end of a wire is located within the space 9. The wedge elements 7 can be provided with teeth capable of piercing the wire coating. This solution is particularly useful in the case when the body 1 and the fastening cone 2 are made in a single piece. Thus, the end of a wire need not be stripped off but a sufficient electrical contact is obtained by means of teeth capable of piercing the coating.

Claims: Claims 1. A sealed terminal for a coated open wire, comprising a body member (1), a clamp element (3) included in the body member for fastening the terminal to an insulator, a cou¬ pling (4, 5, 14) for connecting a branch wire, and a sleeve¬ like fastening socket (2) provided with fastening elements (7) for taking up the mechanical stresses of a wire, c h a r a c t e r i z e d in that the body (1 ) is provided with a wire-end receiving space (9) included in the axial extension of the sleeve-like fastening socket (2) as well as elements (10) extending into said receiving space (9) for providing an electrical contact between the wire end and the body (1) and that said branch-wire coupling (4, 5, 14) partly consists of the body member (1) and partly of a separate coupling element (4) in such a manner that the branch wire is connectable between the coupling element (4) and the body member (1 ) . 2. A terminal as set forth in claim 1, c h a r a c t e r ¬ i z e d in that the coupling element (4) and the body member (1 ) are provided with a first pair of jaws, said jaws including meshed surfaces provided with teeth (5) capable of piercing the wire insulation, and a second pair of jaws including meshed or contact surfaces (6), between which can be fitted a flash barrier horn or a working earth conductor. 3. A terminal as set forth in claim 1, c h a r a c t e r ¬ i z e d in that the base portion of said fastening socket sleeve (2) is surrounded by a locking ring (11) fastened with screws (13) to a bottom (15) included in the body (1), and that between the bottom (15) of the body and said lock¬ ing ring (11) is an annular boss (12) included in the fas¬ tening socket sleeve (2), said boss transmitting the tensile stress of a wire from the sleeve (2) to the locking ring (11) from which the stress of loading transmits by way of said screws (13) to the body member (1). 4. A terminal as set forth in claim 1, c h a r a c t e r ¬ i z e d in that said elements (10) providing an electrical contact are moment screws fitted in threaded holes included in the body member (1 ) . 5. A terminal as set forth in claim 1 or 3, c h a r a c ¬ t e r i z e d in that the sleeve-like fastening socket (2) comprises a per se known conical sleeve, provided thereinside with spring-loaded wedge elements (7) which clamp against the wire surface. 6. A terminal as set forth in any of claims 1-5, c h a r ¬ a c t e r i z e d in that the body member (1 ) is made of profiled aluminium. 7. A terminal as set forth in claim 5, c h a r a c t e r ¬ i z e d in that the wedge elements (7) are provided with teeth capable of piercing the wire coating. 8. A terminal as set forth in claim 7, c h a r a c t e r ¬ i z e d in that the body member (1) and the fastening cone (2) are made in a single piece.

Inventors: TURUNEN HARRI, TURUNEN, HARRI
Applicants: SEKKO AB OY, TURUNEN HARRI, OY SEKKO AB, TURUNEN, HARRI
Application year: 1994
Main classification: H01R4
IPC codes: H01R4, H01R11